General Electric Direct-Air-Cycle Aircraft Nuclear Propulsion Program: XNJ140E Nuclear Turbojet, Section 5. Shield; Section 6. Turbomachinery; Section 7. Control System

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This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency Thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.

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Portions of this document may be illegible in electronic image products. Images are produced from the best available original document.

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COMPREHENSIVE TECHNICAL REPORT AIRCRAFT NUCLEAR PROPULSION PROGRAM red as an account of work d States Government. Neither e United States Atomic Energj f their employees, nor any of ntractors, or their employees, jress or implied, or assumes any 3f any information, apparatus, osed, or represents that its use ely owned rights. United States Atomic Energy Commission Contract No. AT(11-1)-171 (Formerly Aircraft Nuclear Propulsion Department FLIGHT PROPULSION LABORATORY DEPARTMENT AEC RESEARCH AND DEVELOPMENT REPORT

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Col. Ola P. Thorne Lt. Col. Stanley Valcik (2) DTIE (14) plus reproducible master Oak Ridge, Tennessee

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This volume is one of twenty-one summarizing the Aircraft Nuclear Propulsion Program of the General Electric Company. It is a comprehensive technical report of the design and development activities of the XNJ140E Project. Included are a presentation of the design objectives and r e - quirements, an engineering description of the XNJ140E-1 nuclear turbojet engine, supporting analytical design data and methods of calculation, and a brief review of three design studies preceding, and directly applicable to the XNJBeginning early in 1960, a major phase of the national effort leading to the achievement of nuclear powered flight was the design and development of the XNJ140E-1 nuclear turbojet engine to be utilized in an Advanced Core Test program. This program was to demonstrate the capabilities of a ceramic reactor coupled with the appropriate associated components of a direct-air-cycle nuclear turbojet engine. Descriptive material contained in this report is based upon the status of the XNJ140E Project at the time of contract The XNJ140E-1 engine was designed with a reactor of sufficient capability to provide engine performance equivalent to that specified in Department of Defense guidance, which required a speed of Mach 0.8 at an altitude of approximately 35,000 feet in a Convair Model NX 2 aircraft, or equivalent, and an engine life potential of 1000 hours. During this flight condition, the estimated minimum net thrust of the engine The engine contained a reactor-shield assembly coupled with a single set of X211 turbomachinery and arranged in an integral, in-line configuration. The compressor and turbine were separated, but connected by a long coupling shaft. An annular combustor system, using JP-4 jet fuel, was placed in-line between the reactor rear shield and the turbine inlet, and was arranged concentrically around the coupling shaft. The reactor-shield assembly was aprototype of comparable components to be used in subsequently planned flight versions of the engine. Turbomachinery components of improved design and an operational afterburner also would have been The reactor fuel elements were made of a beryllium oxide matrix impregnated with enriched uranium dioxide (~93% u235). tjig uranium dioxide was stabilized with yttrium oxide to limit the conversion of uranium dioxide to higher states of oxidation. Fuel element surfaces exposed to high velocity

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cooling air were coated with zircdnaim oxide stabilized with yttrium oxide; this coating eliminate^uater vapor corrosion of the beryllium oxide. The maximum operating temperature Beryllium oxide was used in the front, rear, and outer r e - flectors. Aluminum oxide was used as the inner reflector and served as thermal insulation between the core and the coupling shaft. Beryllium and stainless steel were used as shielding material in the end shields; each material was used both borated and unborated. Lithium hydride, sealed in stainless steel cans, was used as shielding material in the side This over-all report is divided into four parts. Part A contains section 1., a summary of the report and significant terminology; section 2., precedent studies leading to the selection of the XNJ140E power plant; and section 3., a description of the over-allpowerplant.PartBcontains section 4., a description of the reactor.Part C contains section 5., a description of the shield; section 6., a description of the turbomachinery; and section 7., a description of the control system. Part D contains section 8., a description of test planning, special engineering data instrumentation, and test installations for the Advanced Core Test program; section 9., a discussion of remote handling and maintenance; andsection 10., a discussion of on-site and off-site hazards associated with the operation of the engine during the Advanced Core Acknowledgement is made of technical contributions from many members of the Department's engineering staff and of the many reviews and suggestions of J. I. Trussell.

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5. 2. 1. 4 Coupling Shaft Shield Inserts 32 5. 3. 4. 1 Optimization and Constraints 39 5. 3. 4. 4 Secondary Heating Rates 47 5. 3. 5 Stress and Weights 55 5. 4 Front Shield Component Design Data 55 5. 4. 4 Stress and Weight 79 5. 5 Rear Shield Component Design Data 85

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5. 5. 4 Stress and Weights 103 Side Shield Component Design Data 104 5. 6. 1. 2 Actuator Shielding Pads 119 5. 6. 4 Stress and Weight 139 Miscellaneous Component Design Data 148 5. 7. 1 Coupling Shaft Inserts 148 5. 7. 2. 3 Stress and Weight 150 5. 7. 3 Static Air Seals 150 5. 9. 1 Methods of Computing Direct-Beam Dose Rates 162 5. 9. 1. 1 Neutron Dose Rates 163 5. 9. 2 Methods of Computing Duct Scattering 166 5. 9. 3 Methods of Calculating Secondary Heating Rates 166 5. 9. 3. 1 Absorption of Core-Originated Gamma Rays 166

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5. 9. 3. 2 Kinetic Energy Loss of Fast Neutrons 166 5. 9. 4 Other Nuclear Data 170 5. 9. 6 Nuclear Test Program 176 5. 9. 6. 1 Critical Experiment Facilities 176 5. 9. 6. 2 Foil Activation Analysis 177 5. 9. 6. 4 KEYCE Experimental Data 179 6. 3 Description of Components 189 6. 3. 1. 1 Front Frame Assembly 189 6. 3. 1. 4 Rear Frame Assembly 197 6. 3. 2. 1 Front Frame Assembly 200 6. 3. 2. 4 Rear Frame Assembly 208 6. 3. 8 Accessory Drive System 216 6. 4 Maintenance and Remote Handling 220 6. 4. 2 Provisions for Remote Handling 220 6. 4. 2. 2 Special Remote Handling Devices 223 6. 5. 1 Advantages of the X211-E3 Turbomachinery 223 6. 5. 4 Exhaust Duct and Afterburner 226 6. 6 Engineering Drawing List 227

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7. 2 Engine Control System 230 7. 2. 2 Turbomachinery Control System 232 7. 2. 3 Reactor Control System 233 7. 2. 4 Integration of Turbomachinery and Reactor Control Systems . . . 234 7. 2. 5 Layout of Control and Data Rooms in the FET 236 7. 2. 6 Operator's Console and Data Readout 236 7. 3 Turbomachinery Control System 242 7. 3. 3 Engine Speed Control Subsystem 243 7. 3. 3. 1 Manual Control of Jet Nozzle Area 247 7. 3. 4 Compressor Stator Position Control Subsystem 247 7. 3. 5 Hydraulic Fluid Supply Subsystem 247 7. 3. 6 Manual Fuel Control Subsystem 249 7. 3. 7 Nozzle Bound Control Subsystem 249 7. 3. 8 Thrust Selector Subsystem 249 7. 3. 9. 1 Engine Speed Control Subsystem 252 7. 3. 9. 2 Compressor Stator Position Control Subsystem 252 7. 3. 9. 3 Hydraulic Fluid Supply Subsystem 253 7. 3. 9. 4 Manual Fuel Control Subsystem 253 7. 4 Reactor Control System 253 7. 4. 2 Reactor Startup Subsystem 254 7. 4. 2. 2 Circuitry and Mechanization 262 7. 4. 3 Power Range Temperature and Flux Control Subsystem 275 7. 4. 3. 2 Temperature Loop Circuitry 280 7. 4. 3. 3 Flux Loop Circuitry 283 7. 4. 4 Control Rod Actuation Subsystem 285 7. 4. 4. 4 Transfer Gearbox Assembly 290

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7. 5. 3. 1 Power Safety Circuits 304 7. 5. 3. 2 High Voltage Trips 306 7. 5. 3. 3 High Temperature Trips 308 7. 6. 2. 2 Detailed Operational Requirements 311 7. 6. 2. 3 Procedures for Minimum-Time Transfers 312 7. 6. 2. 4Procedures for Slow Transfers 312 7. 6. 2. 5 Transfer Procedures Using Fully Manual Control . . . . 313 7. 6. 2. 6 Data from Power Transfer Analog Computer

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Anabridgedtableof contents for other parts of this volume is presented below to establish the relationship of this part to the total volume. 1.2 PRECEDENT CERAMIC REACTOR AND ENGINE CONFIGURATION STUDIES 2. PRECEDENT DESIGN STUDIES 2.2 DIOIE REACTOR DESIGN STUDY 2.3 CERAMIC CORE TEST DESIGN STUDY 2.4 ADVANCED CONFIGURATION STUDY 3.3 DESCRIPTION OF THE XNJ140E-1 ENGINE 3.6 JET WAKE AND NOISE DATA 3.7 EFFECTS OF REMOVING CHEMICAL INTERBURNER SYSTEM 4.2 DESCRIPTION OF REACTOR COMPONENTS 4.5 FUEL ELEMENT COMPONENT DESIGN DATA 4.6 OUTER REFLECTOR COMPONENT DESIGN DATA 4.7 INNER REFLECTOR COMPONENT DESIGN DATA 4.8 TRANSITION PIECES COMPONENT DESIGN DATA 4.9 RADIAL ARCHES COMPONENT DESIGN DATA 4.10 CORE LINER AND SHAFT TUNNEL COMPONENT DESIGN DATA 4.11 FORWARD REFLECTOR COMPONENT DESIGN DATA 4.12 AFT-RETAINER ASSEMBLY COMPONENT DESIGN DATA 4.13 RADIAL-SUPPORT-STRUCTURE COMPONENT DESIGN DATA 4.14 CONTROL ROD ASSEMBLY COMPONENT DESIGN DATA 4.15 REACTOR AFTERCOOLING STUDIES 8.2 REACTOR TEST PROGRAMS 8.3 SHIELD TEST PROGRAM 8.4 CONTROL SYSTEM TEST PROGRAM 8.5 ENGINE TEST PROGRAMS

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8.7 TEST SUPPORT EQUIPMENT 8.8 AUXILIARY SUPPORT SYSTEMS 8.9 REACTOR DATA INSTRUMENTATION 8.10 END SHIELD DATA INSTRUMENTATION 8.12 NUCLEAR ENVIRONMENTAL DATA INSTRUMENTATION 8.13 USE OF CONTROL SYSTEM INSTRUMENTATION 8.14 DETAILS OF SENSOR INSTALLATION AND LEAD ROUTING 9.2 ENVIRONMENTAL RADIATION FIELD 9.4 SEPARATION OF THE ENGINE INTO MAJOR SECTIONS 9.5 PROCEDURES FOR HANDLING THE COMPRESSOR SECTION 9.6 PROCEDURES FOR HANDLING THE TURBINE SECTION 9.7 PROCEDURES FOR HANDLING THE REACTOR SECTION 9.8 ENGINE ACCESSORY HANDLING IN THE FET 9.10 SPECIAL FIXTURES FOR REMOTE HANDLING OPERATIONS 10.4 ANALYSIS OF UNCHECKED REACTOR EXCURSIONS AT STARTUP 10.5 NUCLEAR EXCURSIONS DURING OPERATION IN THE CONTROL SYSTSM POWER RANGE 10.6 SECONDARY SCRAM SYSTEM 10.7 LOCAL MELTING DURING OPERATION AT HIGH POWER 10.8 MELTING FOLLOWING ENGINE SHUTDOWN 10.9 MECHANISMS FOR RELEASE OF FISSION PRODUCTS FROM FUEL ELEMENT SURFACES

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5. 2 - Objective fast neutron dose r a t e s per megawatt of reactor power 50 feet from reactor midpoint 21 5. 3 - Objective gamma dose r a t e s per megawatt of reactor power 50 feet from 5. 4 - Control dimensions of XNJ140E-1 shield assembly 23 5. 5 - Isometric cutaway view of XNJ140E-1 front shield assembly 25 5. 7 - Isometric cutaway view of XNJ140E-1 r e a r shield assembly 27 5. 8 - Rear shield ejq)loded isometric cutaway view 28 5. 9 - Cutaway view of XNJ140E-1 side shield assembly 29 5.10 - XNJ140E-1 side shield assembly with major components separated, 5.11 - Lower-half side shield segment 31 5.12 - Coupling shaft shield inserts 33 5.14 - Flow distribution of cooling air in XNJ140E-1 end shields 37 5.15 - Shield sharing concept 40 5. 16 - Definition of angles for shield nuclear data 41 5.17 - Calculated fast neutron dose r a t e s per megawatt of reactor power 50 feet from XNJ140E-1 reactor midpoint 42 5.18 - Calculated gamma dose rates per megawatt of reactor power 50 feet from 5. 19 - External fast neutron isodose pattern during nuclear operation, 5. 20 - External gamma isodose pattern during nuclear operation, XNJ140E-1 5. 21 - External gamma isodose pattern following shutdown from nuclear 5. 22 - Relative after-shutdown gamma dose r a t e s as a function of operating and 5. 23 - Fast neutron isodose pattern in the shield assembly 48 5. 24 - CoUimated differential neutron flux leaving front, side, and r e a r of 5. 25 - CoUimated differential neutron flux leaving front, side, and r e a r of 5. 26 - CoUimated integral neutron flux leaving the front, r e a r , and side of the 5. 27 - Residual gamma - ray dose rates due to induced radioactivity in the *Each part of this volume contains its own list of figures.

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5. 28 - XNJ140E-1 front shield layout 56 5. 29 - Front shield support structure 58 5. 30 - Support structure cylinder 59 5. 31 - Support structure drag links and fittings 60 5. 32 - XNJ140E-1 front shield central island layout 62 5. 33 - Front shield central island, slab 1-3 64 5. 34 - Front shield central island tension rod 65 5. 35 - Front shield outer section isometric cutaway view 66 5. 36 - Front shield outer section, aft assembly 67 5. 37 - Front shield outer section, front shield cone 68 5. 38 - Front shield outer section layout 70 5. 39 - Front shield cone 71 5. 40 - Aerothermal nomenclature, front shield central island 72 5. 41 - Temperature distribution through slab Sll 73 5. 42 - Axial temperature distribution of a typical tension rod and the adjacent shield slabs 300 seconds after a locked rotor scram 75 5. 43 - Drag link temperature as a function of length 76 5. 44 - Drag link average temperature during chemical start 77 5. 45 - Cooling-air flow schematic, front shield outer section 77 5. 46 - Front shield outer section nodal pattern for aerothermal analysis 78 5. 47 - Temperature response during chemical start, front shield outer 5. 48 - Temperature distribution during steady state nuclear operation, front shield outer section 80 5. 49 - Front shield secondary heating rates, longitudinal traverse 81 5. 50 - Front shield secondary heating rates, radial traverse 82 5. 51 - Primary support structure deflections 83 5. 52 - XNJ140E-1 rear shield layout 86 5. 53 - Attachment of rear shield central island to turbine front frame 88 5. 55 - Schematic diagram of rear shield insulation pads 91 5. 56 - Rear shield forward central island 92 5. 57 - Forward and aft central island attachment to turbine front frame 93 5. 58 - Forward central island duct wall 94 5. 59 - Inner strut segments, rear shield forward central island 95 5. 60 - Rear shield aft central island 96 5. 61 - View of rear shield outer section 98 5. 62 - Rear shield outer section 99 5. 63 - Temperature distribution through aft central island 101 5. 64 - Aerothermal characteristics of rear shield outer section 102 5. 65 - XNJ140E-1 side shield layout 106 5. 66 - XNJ140E-1 side shield and cheeks 108 5. 67 - Attachment points of XNJ140E-1 side shield upper and lower halves 109 5. 68 - Interconnection of side shield segments 110 5. 69 - Hinged attachment of side segments I l l 5. 70 - Upper half …